Extendable self-supporting material composites and manufacture thereof

Abstract

Specific composite materials described herein are based on the discovery that certain selections of materials and manufacturing conditions and processes provide unexpectedly improved self-supporting thin-film composite materials. It has been discovered that certain combinations of backing materials, shrink film materials, and manufacturing conditions provide improved composites having highly controllable, readily repeatable, and stable arc shaped cross-web curled structures. In general, the composite materials described herein comprise a dimensionally alterable film such as a polyester shrink film having a first surface and a second surface, and a polyester backing material having a first surface and a second surface, wherein the second surface of the backing material is laminated to the first surface of the dimensionally alterable film. Upon activation of the alterable film, for example upon exposing the composite material comprising the polyester heat shrink film to heat, the composite material can be imparted with an arc shaped cross-web curled structure along it longitudinal width, resulting in resistance to bending in its axial length, and a self-supporting material.

What is claimed is: 
     
       1. A self-supporting composite having an axial length and a longitudinal width, the composite comprising:
 a polyester film backing having a first surface and a second surface; 
 a heat activated polyester shrink film comprising a first surface and a second surface; 
 a polyurethane adhesive disposed between the second surface of the backing and the first surface of the shrink film, wherein the polyurethane adhesive is a water-based polyurethane dispersion selected from the group consisting of a water-based hybrid polyurethane dispersion with epoxy cross-linker and a water-based hybrid polyurethane/acrylic emulsion with epoxy cross-linker, 
 the shrink film being oriented within the composite wherein, upon activation, the shrink film contracts greater along the longitudinal width of the composite than the axial length; 
 and the axial length of the composite has a curvature about the longitudinal width of the composite material induced by heat activation of the shrink film, wherein the curvature is in the shape of an arc and which curvature imparts stiffness to the composite, and wherein the composite material when extended is self-supporting. 
 
     
     
       2. The composite of  claim 1 , wherein the shrink film comprises a polyethylene terephthalate (PET) film. 
     
     
       3. The composite of  claim 1 , wherein the shrink film comprises a polyethylene terephthalate glycol (PETG) film. 
     
     
       4. The composite of  claim 1 , wherein the backing material comprises a polyethylene terephthalate (PET) film. 
     
     
       5. The composite of  claim 1 , wherein the composite has a bond of at least about 35 ounces per inch between the backing and shrink film. 
     
     
       6. The composite of  claim 1 , wherein the polyurethane adhesive is a heat curing adhesive with a minimum curing temperature at or below the heat activation temperature of the shrink film. 
     
     
       7. The composite of  claim 1 , wherein the polyurethane adhesive is a heat curing adhesive with a minimum curing temperature at or above the heat activation temperature of the shrink film. 
     
     
       8. The composite of  claim 1 , wherein the shrink film has a shrink profile from its onset activation temperature to its maximum shrink potential of at least about 30° C. or greater. 
     
     
       9. The composite of  claim 1 , wherein the first surface of the backing material or the second surface of the shrink film further comprises a pressure sensitive adhesive. 
     
     
       10. The composite of  claim 1 , wherein the arc of the induced curvature is between about at least 15° and less than 360°. 
     
     
       11. The composite of  claim 1 , wherein the adhesive disposed between the backing and shrink film is less than about 0.2 mils. 
     
     
       12. The composite of  claim 1 , wherein the adhesive disposed between the backing and shrink film is less than about 0.15 mils. 
     
     
       13. The composite of  claim 1 , wherein the first surface of the shrink film has a surface energy of at least about 35 dynes/cm. 
     
     
       14. The composite of  claim 13 , wherein the first surface of the shrink film has not been activated or treated. 
     
     
       15. The composite of  claim 13 , wherein the first surface of the shrink film has been activated or treated. 
     
     
       16. The composite of  claim 1 , wherein the second surface of the backing has a surface energy of at least about 35 dynes/cm. 
     
     
       17. The composite of  claim 16 , wherein the second surface of the backing has not been activated or treated. 
     
     
       18. The composite of  claim 16 , wherein the second surface of the backing has been activated or treated. 
     
     
       19. The composite of  claim 1 , wherein the polyurethane dispersion is a water-based hybrid polyurethane dispersion with epoxy cross-linker. 
     
     
       20. The composite of  claim 1 , wherein the polyurethane dispersion is a water-based hybrid polyurethane/acrylic emulsion with epoxy cross-linker. 
     
     
       21. A method for manufacturing a self-supporting composite having an axial length and a longitudinal width comprising:
 providing a backing material having a first surface and a second surface; 
 providing a heat shrink film comprising a first surface and a second surface, the shrink film having an onset activation temperature that, when the shrink film is exposed to such temperature, the temperature induces shrinkage within the shrink film; 
 heating a polyurethane adhesive to a temperature that exceeds the activation temperature of the shrink film; 
 applying the polyurethane adhesive to the second surface of the backing material; 
 laminating the second surface of the backing material with the first surface of the shrink film to create the composite, wherein the shrink film is oriented within the composite so that, upon activation, the shrink film contracts greater along the longitudinal width of the composite than the axial length; 
 wherein, at the time of lamination, the temperature of the polyurethane adhesive exceeds the activation temperature of the shrink film inducing the shrink film to activate; and 
 wherein the activation of the shrink film creates a longitudinal curvature about the longitudinal width of the composite material induced by heat activation of the shrink film, wherein the curvature is in the shape of an arc and which curvature imparts stiffness to the composite, and wherein the composite material when extended is self-supporting. 
 
     
     
       22. The method of  claim 21 , wherein the backing material comprises a polyester film, the shrink film comprises a polyester film, and the polyurethane adhesive is selected from the group consisting of a two-component polyurethane, a polyurethane dispersion, a polyurethane dispersion with epoxy cross-linker, and a hybrid polyurethane dispersion/acrylic emulsion. 
     
     
       23. A method for manufacturing a self-supporting composite having an axial length and a longitudinal width comprising:
 providing a backing material having a first surface and a second surface; 
 providing a heat shrink film comprising a film having a first surface and a second surface, the shrink film having an onset activation temperature that, when the shrink film is exposed to such temperature, the temperature induces shrinkage within the shrink film; 
 providing a heat curing polyurethane adhesive having a minimal curing temperature below the initial activation temperature of the shrink film; 
 applying the heat cure polyurethane adhesive to the second surface of the backing material; 
 heat laminating the second surface of the backing material with the first surface of the shrink film to create the composite, wherein the shrink film is oriented within the composite so that, upon activation, the shrink film contracts greater along the longitudinal width of the composite than the axial length; 
 wherein, at the time of lamination, the materials are exposed to a temperature sufficient to cure the adhesive but less than the activation temperature of the shrink film; and, 
 subsequently exposing the composite to a temperature sufficient to activate the shrink film, wherein the activation of the shrink film creates a longitudinal curvature about the longitudinal width of the composite material induced by heat activation of the shrink film, wherein the curvature is in the shape of an arc and which curvature imparts stiffness to the composite, and wherein the composite material when extended is self-supporting. 
 
     
     
       24. The method of  claim 23 , wherein the backing material comprises a polyester film, the shrink film comprises a polyester film, and the heat cure polyurethane adhesive is selected from the group consisting of a two-component polyurethane, a polyurethane dispersion, a polyurethane dispersion with epoxy cross-linker, and a hybrid polyurethane dispersion/acrylic emulsion. 
     
     
       25. A method for manufacturing a self-supporting composite having an axial length and a longitudinal width comprising:
 providing a backing material having a first surface and a second surface; 
 providing a heat shrink film comprising a film having a first surface and a second surface, the shrink film having an onset activation temperature that, when the shrink film is exposed to such temperature, the temperature induces shrinkage within the shrink film; 
 providing a heat cure polyurethane adhesive; 
 applying the polyurethane adhesive to the second surface of the backing material; 
 heat laminating the second surface of the backing material with the first surface of the shrink film to create the composite, wherein the shrink film is oriented within the composite so that, upon activation, the shrink film contracts greater along the longitudinal width of the composite than the axial length; 
 wherein, at the time of lamination, the materials are exposed to a temperature sufficient to cure the adhesive and activate the shrink film; 
 wherein the activation of the shrink film creates a longitudinal curvature about the longitudinal width of the composite material induced by heat activation of the shrink film, wherein the curvature is in the shape of an arc and which curvature imparts stiffness to the composite, and wherein the composite material when extended is self-supporting. 
 
     
     
       26. The method of  claim 25 , wherein the backing material comprises a polyester film, the shrink film comprises a polyester film, and the heat cure polyurethane adhesive comprises an adhesive selected from the group consisting of a two-component polyurethane, a polyurethane dispersion, a polyurethane dispersion with epoxy cross-linker, and a hybrid polyurethane dispersion/acrylic emulsion. 
     
     
       27. A self-supporting composite having an axial length and a longitudinal width, the composite comprising:
 a polyester film backing having a first surface and a second surface; 
 a heat activated polyester shrink film comprising a first surface and a second surface; 
 a heat curing polyurethane adhesive disposed between the second surface of the backing and the first surface of the shrink film, 
 the shrink film being oriented within the composite wherein, upon activation, the shrink film contracts greater along the longitudinal width of the composite than the axial length; 
 and the axial length of the composite has a curvature about the longitudinal width of the composite material induced by heat activation of the shrink film, wherein the curvature is in the shape of an arc and which curvature imparts stiffness to the composite, and wherein the composite material when extended is self-supporting. 
 
     
     
       28. The composite of  claim 27 , wherein the heat curing polyurethane adhesive is selected from the group consisting of a two component polyurethane, a hybrid polyurethane dispersion/acrylic emulsion, and a polyurethane dispersion. 
     
     
       29. The composite of  claim 28 , wherein the heat curing polyurethane adhesive is a polyurethane dispersion selected from the group consisting of a water-based hybrid polyurethane dispersion with epoxy cross-linker and a water-based hybrid polyurethane/acrylic emulsion with epoxy cross-linker. 
     
     
       30. The composite of  claim 27 , wherein the heat curing polyurethane adhesive has a minimum curing temperature at or below the heat activation temperature of the shrink film. 
     
     
       31. The composite of  claim 27 , wherein the heat curing polyurethane adhesive has a minimum curing temperature at or above the heat activation temperature of the shrink film. 
     
     
       32. The composite of  claim 27 , wherein the first surface of the backing material or the second surface of the shrink film further comprises a pressure sensitive adhesive.